David wiley mccaughet



(No Model.)

D. W. MGGAUGHEY. ELECTRIC BURGLAR ALARM.

No. 595,963. Patented Deo. 21,1897.

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UNITED STATES DAVID VILEY MGCAGHEY, OF CHICAGO, ILLINOIS, ASSIGNOR OFSEVEN- TENTHS TO MARION L. SOMERS,

JONES, OF SAME PLACE.

EUGENE R. COX, AND XVARNER E.

ELECTRIC BURGLAR-ALARWL SPECIFICATION forming part of Letters Patent No.595,963, dated December 21, 189'?.

Application filed November 27,1896. Serial No. 613,585. (No model.)

To @ZZ whom t may concern.:

Be it known that I, DAVID `WILEY MC- CAUGHEY, a citizen of the UnitedStates, residing at Chicago, Cook county, Illinois, have inventedcertain new and useful Improvements in Electric Burglar-Alarms, of whichthe following is a specification.

The object of my invention is to provide a simple, economical, andefficient electric burglar-alarm; and the invention consists in thefeatures, combinations, and details of construction hereinafterdescribed and claimed.

In the accompanying drawings, Figure 1 represents my improvements indiagrammatic form as attached to a swinging door; Fig. 2, a.longitudinal sectional view of the contact and inclosing mechanism,shown detached from the door, with the circuitbroken, and taken on line2 of 4t; Fig. 3, a similar view to that shown in Fig. 2, showing theparts in engagement with each other and the circuit closed; and Fig. et,a full-sized end view of either one of the parts.

In the art to which this invention relates it is well known that theusual terminals or contact-points are not protected in any manner otherthan by insulation, so that ordinarily the insulation can be drilledthrough, a short circuit made, and the door or window opened withoutsounding an alarm. My invention is intended, primarily, to obviate thisobjection and provide a simple and economical electric burglar-alarm thecontact-points or terminals of which are protected not only byinsulation, but by an armor, so that they cannot ordinarily be tamperedwith without destroying the circuit.

In constructing a burglar-alarm in accordance with my improvements Imake a terminal A and secure it to an insulated wire a, which I mount ina block B, formed of vulcanized rubber, iiber, or other insulatinginaterial. One end of this block is provided with a hardened-steelsleeve B', that surrounds the same and protects such end from beingdrilled in the ordinary manner. These two parts-the insulated block andthe end sleeve-are ordinarily formed in one integral. piece, though itis not necessary that it should be so, as they can be iitted togetherloosely.

I mount this insulating-block and its sleeve in a metal thimble C, thatis provided with a face-plate portion c, having holes or perforations c'for wood-screws, by which it may be secured to a door or other part withwhich it is intended to be used. Between the shoulder formed by the endof the sleeve B and the inner end of the thimble I insert ahelically-coiled spring D, that normally acts to keep the contact-pointat its outermost limit, as shown in Fig. 2, but will permit of the partsbeing pressed inwardly and below the surface, as shown in Fig. 3, thusforming a cushion for the contact-point. This thimble is inserted in oneend of a hardened-steel tube E, which tube may be placed in the door, asshown in Fig. l of the drawings. The other end of the tube is providedwith an insulating-plug G, having an adjusting-screw g axially enteringthe same, which screw is connected by means of a wire II with a sourceof electric energy. The inner end of the insulated wire that connectswith the terminal is formed into or provided with a helical spring a2,bearing a metal platen a3 on the end thereof, so that when the parts arein the engagement shown in Fig. 3 the platen is forced up against theadjusting-screw, and thus acts to complete the circuit. y

Both of the terminals are constructed exactly the same, with theexception that one of the terminals A2 is sunk below the outerprotecting-sleeve, so that when the parts are together, as shown in Fig.3, they are almost entirely protected,and its block provided with alimiting-shoulder a, Collars h2 limit the movements of the insulatedblocks, as shown in Fig. 2 of the drawings. In placing the thiinbles inposition a hole' e2 is bored in the door and a rather stift helicalspring inserted in the same. The terminal, with its inclosing armor, isforced down against the tension oi this spring and secured in position,the action of the stiff spring' being such that when the securing meansare removed it serves to force thc terminals and incasing armor outsufficiently to obtain a hold of the same and remove it from position.

Referring to diagrammatic view of Fig. l, when the parts are in theposition shown in IOO this gure the main circuit is broken and thearmature-lever I pulled over against the stop t', so that an auxiliarycircuit is formed and current flows from the battery J through Wire l0,alarm l1, wire l2, stop i', armaturelever I, and back by wire 13 tobattery, soundingy an alarm and giving' notice that' the main circuit isinterrupted or broken. lVhen the door is closed, the terminals willoccupy the position shown in Fig. 3 and the main circuit be closed, sothat current flows from the battery through Wire II, through terminal E,thence through terminal E2, through Wire 14, through electromagnets 15,and back by Wire 1G to battery. This energizes the electromagnets l5 andpulls the armature-lever over against the same, thus breaking theauxiliary circuit. The auxiliary circuit is provided with a switch-lever17, so that such circuit may be broken or completed Whenever desired.

lVhile I have described my invention with more or less minuteness asregards details and as being embodied in certain precise forms, I do notdesire to be limited thereto unduly any more than is pointed out in theclaims. On the contrary, I contemplate all proper changes in term,construction, and arrangement, the omission of immaterial elements, andthe substitution of equivalents, as circumstances may suggest ornecessity render expedient.

I claiml. In an electric burglar-alarm, the combination of a terminal orcontact point, a longitudinally-movable insulating-block in which it ismounted, ahard metallic sleeve for protecting one end of theinsulating-block, and an outer hard metallic tube in which the parts aremounted for protecting the same, 4o

substantially as described.

2, In an electric burglar-alarm, the combination of a terminal orcontact point, a longitudinally-movable insulating-block in which it ismounted, a hard metallic sleeve secured to one end of theinsulating-block to protect the same, a thimble in which theinsulatingblock and sleeve are mounted, spring mechanism insertedbetween the thimble and the insulating-block to keep the block With itsterminal point at an outer limit, and an outer encompassing hardmetallic sleeve, substantially as described.

3. In an electric burglar-alarm, the combination of a terminal orcontact point, a lon gitudinally-movable insulating-block in which it ismounted, a hard metallic sleeve secured to one end of theinsulating-block to protect the same, a thimble in which theinsulatingblock is mounted, a helical coiled spring inserted between thethimble and the bloclr` to normally hold the insulating-block at itsouter limit ot motion, an outer encompassing hard metallic sleeve forholding the parts in position and protecting the same, aninsulatingplug` in the end of the tube opposite the terminal point, anadjusting-screw connected with the circuitwire in such insulating-block,and a cushioning-spring on the inner end of the terminal wire arrangedto contact the adjusting-screw and close thc circuit when the parts arein their inner position, substantially as described.

DAVID 'WILEY llICCAUGIlEY.

Witnesses:

THoMAs B. McGuire-ort, THOMAS F. SHERIDAN.

